"Energy drinks could cause public health problems, says WHO study," The Guardian reports. A new review discusses the potential harms of these drinks, especially when they are mixed with alcohol…

“Energy drinks could cause public health problems, says WHO study,” The Guardian reports. A new review discusses the potential harms of these drinks, especially when they are mixed with alcohol.

Energy drinks, such as Red Bull and Monster, contain high levels of caffeine, which is a stimulant. They have become increasingly popular over the last 20 years, especially with young people, with many clubbers mixing them with alcohol.

The Guardian reports on a new review by the World Health Organization (WHO), which reviewed the literature on the associated health risks and policies related to energy drinks. The review was prompted by concerns raised both by the scientific community and among the general public about the health effects of these drinks. It should be noted that although the researchers were from WHO, the review's conclusions do not necessarily represent the decisions or stated policy of WHO.

The researchers described a number of potential health risks, mainly associated with the high caffeine content of the drinks, as well as the risks of combining them with alcohol. They also found that policy regarding energy drinks is limited and call for more long-term research and policy action, to minimise the risk of harm from heavy and long-term energy drink consumption.

As this is a narrative rather than a systematic review, we don’t know if all relevant literature has been included or whether other researchers reviewing the same topic would reach the same conclusions.

With a narrative review there is always the possibility that the evidence has been “cherry-picked” – that is, evidence that supports the researchers’ arguments is included, but contrasting evidence is ignored. However, we would be surprised if this was the case here, as WHO researchers have a well-deserved reputation for impartiality and integrity.

What are energy drinks?

Although there is no standard definition of an “energy drink”, it is taken to mean a non-alcoholic drink that contains caffeine, taurine (an amino acid) and vitamins, in addition to other ingredients.

They were originally introduced in Japan during the 1960s and became increasingly popular in Europe during the 1980s and 90s, possibly due to the rise of rave culture.

It is now commonplace, especially among young people, to mix energy drinks with alcoholic spirits. Many pubs and clubs will sell jugs or “goldfish bowls” of Red Bull and vodka.

Energy drinks are marketed for their perceived or actual benefits as a stimulant, for improving performance and increasing energy. Companies often have sponsorship deals with extreme sport franchises, presumably to sell the message that energy drinks are “edgy and energetic”.

They are now big business. In the EU, it is estimated that 30% of adults and 68% of adolescents consume energy drinks, with global sales estimated to be around $12 billion in 2012.

What are the risks associated with energy drink consumption?

The researchers state that the health risks associated with energy drink consumption are primarily related to their caffeine content.

Energy drinks also contain a variety of other ingredients, such as guarana, and the effect of long-term regular consumption of the combination of the substances in energy drinks is unknown.

The increasing practice of mixing energy drinks with alcohol also carries risks. The researchers state that the consumption of high amounts of caffeine (as found in energy drinks) reduces drowsiness without diminishing the effects of alcohol, resulting in “wide awake drunkenness.” Therefore, there is the risk that people will engage in risky and dangerous behaviour, such as violence or unprotected sex, as the mix of alcohol and caffeine can lead to a loss of inhibition.

What policies exist to regulate the labelling, distribution and sale of energy drinks?

Energy drinks can be sold in all EU member states. Since 2004, energy drinks that contain at least 150mg/l of caffeine have enforced additional caffeine labelling under European regulations. From 2014, these will be labelled with, “High caffeine content. Not recommended for children or pregnant or breastfeeding women,” and the caffeine content will also be expressed in mg/100ml.

Some countries have additional regulations – in Sweden, for example, sales of some products are restricted to pharmacies, and sales to children under 15 are banned.

What policies do the researchers suggest?

The researchers suggest the introduction of the following policies:

an evidence-based, upper limit for the amount of caffeine allowed in a single serving of any drink

a restriction in sales to children and adolescents

the education of healthcare providers to recognise caffeine intoxication, withdrawal and dependence

regulation of the marketing of energy drinks; for example, a ban on adverts that are obviously designed to target young people or suggest an association between energy drinks and sporting prowess

What future work do the researchers suggest?

The researchers state that more research is required to discover the effects of long-term energy drink consumption, particularly among children and young adults, and the best ways to restrict their usage.

What are the researchers' conclusions?

The researchers conclude that: “The health risks associated with energy drink consumption are primarily related to their caffeine content, but more research is needed that evaluates the long-term effects of consuming common energy drink ingredients. The evidence indicating adverse health effects due to the consumption of energy drinks with alcohol is growing. The risks of heavy consumption of energy drinks among young people have largely gone unaddressed and are poised to become a significant public health problem in the future.”

What's important to realise is that energy drinks contain caffeine, often in large quantities. This could pose a risk to your health if consumed in high quantities and/or mixed with alcohol.